This invention relates to a traffic control system particularly suitable for aiding blind pedestrians to cross street intersections having traffic control lights. The invention relates, more particularly, to a traffic control system for aiding blind pedestrians which includes an interrogating unit incorporated into a cane and a responding unit operatively associated with the traffic signal light control circuits.
Traffic control systems are in wide use in the United States and elsewhere in which traffic signal lights at a street intersection are controlled automatically by timing circuits. In many instances, control boxes are provided with buttons, which may be operated by pedestrians, for either effecting or pre-empting control of the signal lights to provide a visual signal indicating that the signal lights are in such an operative condition that pedestrians may safely cross the intersection. In some cases, an audible signal may be provided as well from a loud speaker mounted in the vicinity of the intersection.
Many aids for blind pedestrians are known. Specially equipped canes are known; for example, a cane having mechanical means to detect obstacles in the path of a blind person is disclosed in U.S. Pat. No. 3,158,851. A cane using laser means and rather complicated optics for sending light signals and receiving, in reply, a return signal is known from U.S. Pat. No. 3,546,467.
U.S. Pat. No. 3,366,922 contains a disclosure of a system which includes a device worn like spectacles, an acoustic wave being transmitted to be reflected so as to be received by spaced receivers carried by the device, audible signals being produced in earphones. Apparatuses of similar type and purpose are disclosed in U.S. Pat. Nos. 3,742,433 and 3,718,896.